What event led to the change of the political regime in 1814?

If we are talking about France, then it was Napoleon’s defeat at the Battle of Waterloo that led to a change in the political regime here. This is a “sad event” for the “restoration” of the Bourbon monarchy. After that, Louis XVIII again ascended the throne. By the way, this monarch was the last in this state who was not overthrown as a result of revolutionary actions. He died in 1824, at that time he was only sixty-eight years old. He was married only once, he had no children.